This invention relates in general to pipe laying equipment and, in particular, to a method of and apparatus for continuously laying pipes of large dimensions.
More specifically, but without restriction to the particular use which is shown and described, this invention relates to a method of and apparatus for continuously laying large dimension pipe wherein two self-propelled vehicles are utilized with one of the vehicles having two movable-arm cranes, one for maneuvering the pipe and another for attachment to the second self-propelled vehicle which functions as a counterweight during pipe laying operation.
The use of self-propelled counterweighted vehicles for various vehicle-mounted implements is well known. Some typical examples of such vehicles are disclosed in U.S. Pat. Nos. 3,815,478; 3,851,712; and 3,853,231; and the references cited therein. Each of the vehicles utilizes various counterweight apparatus and counterweight actuating systems for balancing the vehicle during operation of the various vehicle-mounted implements. While the systems described and disclosed therein may be satisfactory for certain purposes, they all add a great deal of weight to the vehicle, increase vehicle size, and decrease the operational speed of the vehicle when the vehiclemounted implement is not being utilized caused by the uneven distribution of the attached counterweight.
It is, therefore, an object of this invention to improve methods of and apparatus for laying pipes by self-propelled vehicles.
Another object of this invention is to increase operational capacity of pipe laying vehicles.
It is another object of this invention to increase operational speed of pipe-laying vehicles.
These and other objects are obtained in accordance with the present invention wherein there is provided a pipe-laying vehicle having a movable-arm lifting crane for laying pipe and a movable-arm balancing crane for operative attachment to a counterweight. The counterweight for balancing the pipe-laying vehicle during operation is provided by a second self-propelled vehicle attachable to and detachable from the movable-arm balancing crane such that counter-balancing is effected during pipe-laying operation, but may be detached during other operation or movement of the pipe-laying vehicle.